The long-term goal of this project is to sensitize human melanomas to hyperthermia and radiation therapy. Towards this end, we propose to employ non-invasive NMR and near infrared (NIR) imaging methods to monitor human melanomas in nude mice. Our Overall Hypothesis is that optimal sensitization of human melanomas to hyperthermia and radiation therapy will be achieved of hyperglycemia in conjunction with inhibition of specific pathways of mitochondrial metabolism and cellular acid/base transport. To test this hypothesis, we will pursue the following Specific Aims: 1) Employ multi-nuclear NMR imaging/spectroscopy methods, to delineate the effects of hyperglycemia and inhibition of mitochondrial metabolism and ion transport; these methods will monitor intracellular and extracellular pH & bioenergetics (by 31P MRS), steady state levels of lactate (by 1H MRS), intracellular sodium concentration (by multiple quantum coherence transfer 23Na MRI) and perfusion (by 1H{17O}T1 MRI using H2 17O as a marker. 2) Develop and compare 1H{17O} and 13C NMR methods for monitoring tumor oxygen consumption rates in culture and in vivo, and use these methods to monitor the Crabtree effect in human melanomas. The 1H{17O} MRI method will monitor reduction of 17O2 to H217O; the arterial input function required for fitting data to the Kety equation will be determined simultaneously by imaging the heart at diastole). We will validate and utilize a metabolic network model to monitor glycolytic and TCA cycle flux during hyperglycemia and following inhibition of mitochondrial metabolism and ion transport. NIR imaging will monitor vascular oxygenation. 3) By NMR methods monitor the effects of tumor acidification (achieved by methods described in Aim 1) during hyperthermia conducted on in vivo melanomas in the magnet.